Profile of chicken macrophage functions after exposure to catecholamines in vitro

The effects of catecholamines (CA) on various chicken macrophage functions were examined. Macrophage monolayers were exposed to .01, .1, .25, 1, 2, and 5 micrograms/mL of dopamine (DA), norepinephrine (NE) and epinephrine (E) for 1 hr. All CA were toxic for macrophages at 1-5 micrograms dose range resulting in 25-50% cell death. All CA at the .1 and .25 micrograms/mL level increased E. coli and sheep red blood cells (SRBC) phagocytosis by macrophages. The percentage of Fc-receptor positive macrophages increased after CA exposure. Prolonged exposure of macrophages (3 hr) reduced SRBC phagocytosis by DA-treated but not in NE- and E-treated macrophages. However, after 1 hr exposure and 3 hr recovery period, CA-induced changes were reversed in all but DA-treated cultures. Apomorphine and metoclopromide blocked DA whereas propranolol blocked NE and E effects suggesting specificity of the observed effects via catecholaminergic receptors on chicken macrophages. Dopamine and NE (.25 micrograms/mL) did not affect but E exposure enhanced LPS-induced tumoricidal factor production. These findings suggest that CA modulate chicken macrophage effector functions.